I have (2) retro fitted LED Grand AM 3rd brake/trunk lights, using a LED board from a Impala. This is in the Stock Grand Am 3rd tail light housing and uses the Grand Am connector. PLUG and PLAY. NO RE-WIRING OR SPLICING REQUIRED. All lights are tested and work perfectly.
$35 shipped US/Canada

With the Impala unit, there is a clear light dispursing lense that came with it. This was modified to fit under the Grand Am lense (Included) and you can use it if you wish, or use it without. Optional.
If you do want to use it, it just squeezes in behind the red lense and comes between the LED strip and the red tail light. See pics